“This is 40”

Rating: R

When: Opens Friday

Where: Wide release

Running time: 2 hours, 13 minutes

★★

Director Judd Apatow (“The 40-Year-Old Virgin”) has been tracking the maturation of the American male through adolescent comedies that are sentimental at heart. In 2007’s “Knocked Up,” he explored how two 20-somethings, a pot-smoking loser named Ben (Seth Rogen) and Alison, an ambitious reporter (Katherine Heigl), were dragged into adulthood when a one-night stand resulted in a pregnancy. It was in this film that Apatow introduced Debbie (played by his real-life wife Leslie Mann) and Pete (Paul Rudd), a 30-something couple going through the growing pains that come with marriage and kids.

In “This is 40,” Apatow turns his full attention to the pair, who are both turning the dreaded 4-0 the same week. Their marriage is strained by the overwhelming sense of responsibility that comes with having two children (played sweetly by Apatow and Mann’s own daughters, Iris and Maude), maintaining all the trappings of an overextended, upper-middle-class lifestyle, and keeping the passion and affection for each other on something more than life support.

Because he wrote the script and cast his own family in their corresponding roles, it’s hard not to see Pete as a stand-in for Apatow. This adds an air of voyeurism as we watch the couple grapple with the typical demands of domestic life (bickering siblings, fading sex life, financial troubles) taken to vulgar extremes with the director’s liberal use of the f-bomb, literal toilet (and anus) humor and outrageous insults, which can inspire some laughs — assuming you’ve laughed at this kind of stuff before.

But there’s something uncomfortable about it, too, particularly when the husband and wife go after each other with a level of resentment and anger that seems to doom the marriage to failure. It’s great that Apatow isn’t afraid to dig deep to mine the uglier sides of matrimony (how do you fantasize your partner’s death?), but his unusual personal connection to the material and the cast, and the uncharacteristic bitterness that the normally affable Rudd brings to Pete, is somewhat off-putting.

There’s an awful lot of action packed into what is supposed to be a one-week period, and plenty of peripheral storylines that stretch the film into an unnecessary 133 minutes. There’s Pete’s mooching dad (a well-cast Albert Brooks) and Debbie’s distant father (John Lithgow), both of whom have second families and get some of the blame for the struggling couple’s issues (oddly, there’s no mention of what happened to their mothers). There’s the aging real-life rocker Graham Parker, whom Pete risks his record label — and his family’s home — to promote, and the sexy salesgirl (Megan Fox) who gives Debbie a dose of youth to yearn for, but who also might have stolen a large sum of money from Debbie’s shop (a matter that Apatow allows Debbie to grossly mishandle without any accountability).

Other tertiary characters present themselves as opportunities for the director to riff with his favorite comedic performers, like Jason Segel as Debbie’s cocky personal trainer, Melissa McCarthy’s trigger-tempered mother, even a blip of an appearance by the rising star writer, director and actor Lena Dunham (HBO’s “Girls”).